Because exposure to radiation is associated with potentially serious health risks, researchers are concerned about the increasing use of radiation for medical purposes. A double-edged sword, radiation can be used to effectively diagnose and treat individuals, but it can also cause subsequent cancers and other conditions.

According to the United Nations Scientific Committee on the Effects of Atomic Radiation, medical use of radiation is not only growing, it is the largest man-made source of exposure to ionizing radiation. To learn more about long-term effects of radiation used in health care settings, epidemiologists are tracking people who have been exposed to medical radiation, noting details such as which individuals may be especially sensitive and whether interactions with other therapies, medical conditions, or lifestyle factors may come into play.